Control devices for a vehicle network such as, for example, CAN, FlexRay or LIN have been known for a long time. The control devices have in common the fact that they have a microprocessor and a transceiver and are suitably connected to the corresponding bus lines. Switching on an operating signal causes all the control devices to be switched on here. This operating signal is usually terminal 15 (KL 15) in the case of a motor vehicle with an internal combustion engine, that is to say the means of switching on the ignition. Furthermore, control devices are known which, when the ignition is switched off, are switched into a sleep mode in order to wake up, and if appropriate to awaken or switch on further control devices, when a specific signal occurs. Such a control device is, for example, the control device for a central locking system. A problem in modern motor vehicles is the increased electrical energy requirement which also brings about an increased fuel consumption in vehicles with internal combustion engines.